Weight percentages and mass accumulation rates of biogenic components in sediment core RC11-210 (Table 1)

High-resolution records of the concentration and mass accumulation rate (MAR, or flux) of biogenic sediments from core RC11-210 in the central equatorial Pacific are compared for the entire late Pleistocene. The fluxes of calcium carbonate and organic carbon correlate well. The opal flux pattern shows no direct correlation with the other two; rather, opal flux maxima correlate with slopes of (i.e. both precede and follow) the organic carbon and carbonate MAR peaks. Organic carbon and calcite therefore may both be better indicators of past productivity than opal, which is an indicator of transition at this location. We interpret the sequence low biogenic fluxes, high opal fluxes, high carbonate, carbon, and opal fluxes as representing the transition from low to high sea surface biological productivity. The phase relationships for eccentricity of the biogenic sedimentation records were compared to those of other climatic indications including the oxygen isotope record of ice volume, the ice core CO2 record, the Pacific delta13C record, the deep nutrient (Cd/Ca) record, and the eolian grain-size record of wind intensity. We find that starting from maximum ice volume (phase angle of 0°) the phase relationships of the 100,000-year periodicity show, in the first quadrant, maximum wind intensity (30°) and maximum calcite and carbon flux (45°) occurring first, followed by maximum opal flux (75°) and then maximum deep nutrients (95°). Minimum Pacific delta13C occurs at a phase angle of 155°, the maximum CO2 in the Vostok record and minimum ice volume is at 180°. Thus, in the eccentricity climate cycle, glacial conditions lead to stronger wind-driven circulation which enhances productivity which in turn results in enhanced oceanic and atmospheric carbon dioxide and minimum ice volume.

针对赤道太平洋中部RC11-210岩芯获取的晚更新世全时段生源沉积物浓度与质量累积速率（mass accumulation rate，MAR，又称通量）的高分辨率记录，开展对比分析。碳酸钙与有机碳的通量呈现显著正相关；而蛋白石通量与二者均无直接关联，其峰值反而与有机碳、碳酸钙MAR峰值的升降阶段（即蛋白石通量峰值既先于该峰值出现，也滞后于该峰值）存在对应关系。因此相较于作为该区域环境转换指标的蛋白石，有机碳与方解石或许更适合作为古生产力的代用指标。我们将“低生源通量、高蛋白石通量，再到高碳酸盐、碳及蛋白石通量”的序列，解读为海表生物生产力从低到高的转变过程。将生源沉积记录的偏心率相位关系，与其他气候代用指标进行对比，包括冰量氧同位素记录、冰芯二氧化碳记录、太平洋δ¹³C记录、深层营养盐（镉钙比）记录以及指示风力强度的风尘粒度记录。研究发现，以冰量最大值（相位角0°）为起点，10万年周期的相位关系依次为：第一象限内首先出现最大风力强度（30°）与最大方解石、碳通量（45°），随后为最大蛋白石通量（75°），再之后为最大深层营养盐浓度（95°）。太平洋δ¹³C最小值出现在相位角155°处，沃斯托克冰芯记录的二氧化碳最大值与冰量最小值则对应180°相位角。综上，在偏心率驱动的气候周期中，冰期环境会催生更强的风力驱动环流，进而提升海洋生产力，最终促成海洋与大气二氧化碳浓度升高、冰量降至最低。